A wireless local area network (WLAN) is typically made up of a number of “access points” (APs). Each access point is responsible for transmitting information to a plurality of mobile devices (e.g., wireless laptop computer, etc.) that are within the transmission range of the AP. The area within which a mobile device can effectively receive a wireless transmission from an AP is called the coverage area of an AP.
Many times, the coverage areas of one or more APs overlap. When this occurs, a mobile device may be able to receive a transmission from one or more APs. Though a mobile device may be able to receive a transmission from more than one AP, the signal strength of each transmission may not be the same. More particularly, a transmission a mobile device receives from one AP may have a high signal-to-noise ratio (SNR) while the transmission the mobile device receives from another AP may have a low SNR. Of course, there may be occasions when the SNRs are the same, indicating that the mobile device can receive a transmission from either AP at the same signal strength.
Depending on the received SNR, as well as other factors, a mobile device will decide which AP or APs to communicate with. Knowledge of the coverage areas of APs aids in this decision-making process. It is, therefore, desirable to be able to determine the extent to which coverage areas of APs overlap or share common coverage points.
Along with coverage areas, it is also desirable to determine how far apart one AP is from another in order to, for example, identify holes in the overall coverage area of a WLAN.